Lithium-Ion (“Li-Ion”) 18650 cells (and other batteries) all have a slight chance of spontaneously shorting which heats the interior gradually to 130 C where the “separator” film melts. That triggers an explosive release of electric energy, where the end cap ruptures, a flare emerges briefly (˜1 s), and then for a minute or so the cell materials combust, releasing heat and driving the cell to temperatures T greater than 500 C.
Neighboring cells can be heated above the critical 130 C at which they also short with the same consequences, known as “thermal runaway propagation.” The Boeing battery problem is of this nature. Tesla batteries handle this problem with an active cooling system. There is a desire to seek a passive solution suitable for battery modules of arbitrary cell sizes.
Therefore, there exists a need for a new system, method, and apparatus for preventing thermal runaway propagation in a battery system.